US20090274608A1 - Calcium-silicate based slag for treatment of molten silicon - Google Patents
Calcium-silicate based slag for treatment of molten silicon Download PDFInfo
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- US20090274608A1 US20090274608A1 US12/501,725 US50172509A US2009274608A1 US 20090274608 A1 US20090274608 A1 US 20090274608A1 US 50172509 A US50172509 A US 50172509A US 2009274608 A1 US2009274608 A1 US 2009274608A1
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- silicate based
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/037—Purification
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/24—Alkaline-earth metal silicates
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0087—Treatment of slags covering the steel bath, e.g. for separating slag from the molten metal
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/076—Use of slags or fluxes as treating agents
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- the present invention relates to a calcium-silicate based slag having a very low phosphorous content, a method for producing such calcium-silicate based slag having a very low phosphorous content, and to the use of the calciumsilicate based slag for the removal of boron and phosphorous from molten silicon.
- the phosphorous content of solar grade silicon should be less than 3 ppmw.
- the slag treatment of silicon in order to remove boron also influences the phosphorous content of silicon.
- the distribution coefficient between phosphorous in slag and phosphorous in silicon is very low and in the range between 0.1 and 0.3. If calcium-silicate based slag used to remove boron from silicon contains too much phosphorous, the phosphorous content of silicon can therefore be increased during the slag treatment. It is thus important to use a low phosphorous containing calcium-silicate based slag for removal of boron from silicon.
- the phosphorous content of the calcium-silicate based slag should be as low as possible and preferably well below 3 ppmw.
- the present invention relates to a calciumsilicate based slag for treatment of molten silicon, said slag having a phosphorous content of less than 3 ppmw.
- the calcium-silicate based slag has a phosphorous content below 1 ppmw.
- the calcium-silicate based slag contains CaF 2 and/or MgO in an amount of up to 30% by weight in order to lower the viscosity of the slag and to increase removal of phosphorous and boron from silicon.
- the calcium-silicate based slag contains one or more of BaF 2 , BaO, LiF and Li 2 O in an amount of up to 10% by weight in order to adjust the density of the slag to facilitate removal of the slag from silicon after slag treatment.
- the calciuin-silicate based slag contains AI 2 0 3 in order to be able to adjust the aluminum content of silicon to be treated with the slag.
- the present invention relates to a method for producing a low phosphorous calcium-silicate based slag, which method is characterized in that molten calcium-silicate based slag is treated with a molten ferrosilicon alloy in a vessel whereby phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy, and separating the molten low phosphorous calcium-silicate based slag from the molten ferrosilicon alloy.
- a molten layer of a ferrosilicon alloy is provided in the vessel, whereafter a Si0 2 source, a CaO source are supplied to the top of the layer of ferrosilicon alloy to provide a layer of molten calciumsilicate based slag whereby phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy, and removing the low phosphorous calcium-silicate based slag from the vessel.
- the ferrosilicon alloy comprises up to 30% by weight silicon, the remaining being iron except for normal amounts of impurities. More preferably the ferrosilicon alloy comprises 10-20% by weight silicon.
- the amount of silicon in the ferrosilicon alloy should balance the amount of Si0 2 in the liquid calcium-silicate based slag in order to prevent silicon in the slag from entering the ferrosilicon alloy and thus changing the composition of the slag.
- the molten ferrosilicon alloy can be produced in situ by adding Fe203 and Si together with the slag forming compounds Si0 2 and CaO. Upon heating Fe203 will be reduced to Fe by some of the Si added and form the ferrosilicon alloy.
- the amount of Si0 2 supplied may have to be adjusted in order to compensate for the amount of Si0 2 produced when Fe203 is reduced by Si, in order to obtain a suitable final composition of the calcium-silicate based slag.
- a reducing and/or an inert gas or a mixture of such gases are supplied to the vessel in order to stir the layers of molten ferrosilicon and liquid calcium-silicate based slag.
- carbon monoxide and hydrogen are supplied as reducing gases and argon and nitrogen are supplied as inert gases.
- the calcium-silicate based slag treated for removal of phosphorous is slag which has been used for slag treatment of molten silicon and thus has an increased content of phosphorous.
- calciumsilicate based slag from treatment of molten silicon can be regenerated and recycled thus strongly reducing the costs for slag treatment of molten silicon and avoiding disposal of large volumes of used calcium-silicate based slag.
- the method of the present invention can be carried out in conventional high temperature furnaces such as induction furnaces and arc furnaces.
- an arc furnace having vertical electrodes and equipped with a lower tapping hole near its bottom and an upper tapping hole at a higher level.
- the process is started by establishing a layer of molten ferrosilicon alloy at the bottom of the furnace, where the top of the layer of ferrosilicon is well below the upper tapping hole.
- slag forming compounds or used slag for regeneration is added until a layer of molten slag extending a distance above the upper tapping hole is formed.
- the molten layer of slag is allowed to stay in the furnace for a predetermined period to ensure removal of phosphorous from the slag and into the ferrosilicon alloy.
- the upper tapping hole is then opened and the slag above the tapping hole is being tapped from the furnace. After tapping, the upper tapping hole is closed and further slag forming compounds are supplied to the furnace. When the phosphorous content in the ferrosilicon alloy has increased to a preset value, the ferrosilicon alloy is tapped from the lower tapping hole and the above described process is repeated. In this way it is obtained a semi-continuous, low cost production of low phosphorous calcium-silicate based slag.
- the present invention also relates to the use of the slag produced according to the method of the present invention for removal of boron and phosphorous from molten silicon.
- a layer of molten ferrosilicon alloy consisting of 85% by weight Fe and 15% by weight Si was provided at the bottom of an induction furnace. 120 grams of 10 quarts having a phosphorous content of 4 ppmw and 130 grams of lime having a phosphorous content of 35 ppm were added to the induction furnace and melted on the top of the molten ferrosilicon layer. The initial phosphorous content of the liquid slag was calculated to 20 ppmw based on the phosphorous content of quarts and lime.
- Table 1 show that the phosphorous content in the produced slags was below the detection limit of 2.5 ppm for all three slags. Based on calculations of mass balances from use of the produced slags in slag treatment of molten silicon, it was found that the phosphorous content of the three slags produced in fact was about 0.1 ppmw. Further, Table 1 shows that the content of Fe203 in the three slags was very low, indicating that only a minor amount of iron was transferred from the ferrosilicon alloy to the slag phase.
- the three slags A, Band C produced in Example 1 were used to remove boron and phosphorous from molten silicon.
- Molten metallurgical grade silicon containing 47 ppmw boron, 9 ppmw phosphorous and 0.25% by weight of iron was treated with the slags A, Band C produced in Example 1.
- the weight ratio of slag to silicon was 2.6 for all runs.
- the content of phosphorous, boron and iron in the used slags and in the treated silicon were analysed. The results are shown in Table 2.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Metallurgy (AREA)
- Materials Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Silicon Compounds (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
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- Silicates, Zeolites, And Molecular Sieves (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
Description
- This application is a divisional application of the U.S. application Ser. No. 10/515,583, which is a 371 of PCT/NO03/00091 filed Mar. 17, 2003, which claimed the priority of Norwegian Patent Application No. 20022409 filed May 22, 2002. The contents of all three applications are incorporated herein by references and priority of all these application is claimed.
- The present invention relates to a calcium-silicate based slag having a very low phosphorous content, a method for producing such calcium-silicate based slag having a very low phosphorous content, and to the use of the calciumsilicate based slag for the removal of boron and phosphorous from molten silicon.
- In the method of refining metallurgical grade silicon in order to produce pure silicon for solar cell production (solar grade silicon) it is known to remove boron by treatment of molten silicon with a calcium-silicate based slag. Such a method is disclosed in U.S. Pat. No. 5,788,945. In order to remove boron from silicon to an acceptable low level it is necessary to use a slag having a low boron content.
- For solar grade silicon there is also strict requirements to the content of phosphorous. Thus the phosphorous content of solar grade silicon should be less than 3 ppmw.
- The slag treatment of silicon in order to remove boron also influences the phosphorous content of silicon. Thus the distribution coefficient between phosphorous in slag and phosphorous in silicon is very low and in the range between 0.1 and 0.3. If calcium-silicate based slag used to remove boron from silicon contains too much phosphorous, the phosphorous content of silicon can therefore be increased during the slag treatment. It is thus important to use a low phosphorous containing calcium-silicate based slag for removal of boron from silicon.
- When preparing phosphorous containing calcium-silicate based slag from CaO and Si02 it is difficult to find a CaO source having a sufficiently low phosphorous content. In order not to increase the phosphorous content of silicon during slag treatment the calcium-silicate based slag, the phosphorous content of the calcium-silicate based slag should be as low as possible and preferably well below 3 ppmw.
- It is an object of the present invention to provide a calcium-silicate based slag having a very low phosphorous content and a method for removing
- phosphorous from calcium-silicate based slag where low cost sources of CaO and Si02 can be used to produce the slag.
- Thus, according to a first aspect the present invention relates to a calciumsilicate based slag for treatment of molten silicon, said slag having a phosphorous content of less than 3 ppmw.
- According to a preferred embodiment the calcium-silicate based slag has a phosphorous content below 1 ppmw.
- According to a preferred embodiment the calcium-silicate based slag contains CaF2 and/or MgO in an amount of up to 30% by weight in order to lower the viscosity of the slag and to increase removal of phosphorous and boron from silicon.
- According to another preferred embodiment the calcium-silicate based slag contains one or more of BaF2, BaO, LiF and Li2O in an amount of up to 10% by weight in order to adjust the density of the slag to facilitate removal of the slag from silicon after slag treatment.
- According to yet another preferred embodiment the calciuin-silicate based slag contains AI203 in order to be able to adjust the aluminum content of silicon to be treated with the slag.
- According to a second aspect the present invention relates to a method for producing a low phosphorous calcium-silicate based slag, which method is characterized in that molten calcium-silicate based slag is treated with a molten ferrosilicon alloy in a vessel whereby phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy, and separating the molten low phosphorous calcium-silicate based slag from the molten ferrosilicon alloy.
- According to a preferred embodiment a molten layer of a ferrosilicon alloy is provided in the vessel, whereafter a Si02 source, a CaO source are supplied to the top of the layer of ferrosilicon alloy to provide a layer of molten calciumsilicate based slag whereby phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy, and removing the low phosphorous calcium-silicate based slag from the vessel.
- Preferably the ferrosilicon alloy comprises up to 30% by weight silicon, the remaining being iron except for normal amounts of impurities. More preferably the ferrosilicon alloy comprises 10-20% by weight silicon. The amount of silicon in the ferrosilicon alloy should balance the amount of Si02 in the liquid calcium-silicate based slag in order to prevent silicon in the slag from entering the ferrosilicon alloy and thus changing the composition of the slag.
- According to another embodiment, the molten ferrosilicon alloy can be produced in situ by adding Fe203 and Si together with the slag forming compounds Si02 and CaO. Upon heating Fe203 will be reduced to Fe by some of the Si added and form the ferrosilicon alloy. In this embodiment the amount of Si02 supplied may have to be adjusted in order to compensate for the amount of Si02 produced when Fe203 is reduced by Si, in order to obtain a suitable final composition of the calcium-silicate based slag.
- In order to increase the speed of reaction between the molten calcium-silicate based slag and the molten ferrosilicon alloy a reducing and/or an inert gas or a mixture of such gases are supplied to the vessel in order to stir the layers of molten ferrosilicon and liquid calcium-silicate based slag. Typically, carbon monoxide and hydrogen are supplied as reducing gases and argon and nitrogen are supplied as inert gases.
- By the method of the present invention it has surprisingly been found that practically 100% of the phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy. Further, only a small amount of iron is being transferred from the ferrosilicon alloy to the calcium-silicate based slag.
- By the method of the present invention it is thus possible to produce a calcium-silicate based slag having a phosphorous content of below 1 ppmw from a calcium-silicate slag which initially at least 30 ppmw phosphorous.
- Cheap sources of lime and quarts can thus be used to provide a high quality calcium-silicate based slag which is excellent for the removal of boron and phosphorous from molten silicon.
- In one embodiment the calcium-silicate based slag treated for removal of phosphorous is slag which has been used for slag treatment of molten silicon and thus has an increased content of phosphorous. In this way calciumsilicate based slag from treatment of molten silicon can be regenerated and recycled thus strongly reducing the costs for slag treatment of molten silicon and avoiding disposal of large volumes of used calcium-silicate based slag.
- The method of the present invention can be carried out in conventional high temperature furnaces such as induction furnaces and arc furnaces.
- In a preferred embodiment it is used an arc furnace having vertical electrodes and equipped with a lower tapping hole near its bottom and an upper tapping hole at a higher level. The process is started by establishing a layer of molten ferrosilicon alloy at the bottom of the furnace, where the top of the layer of ferrosilicon is well below the upper tapping hole. Thereafter slag forming compounds or used slag for regeneration is added until a layer of molten slag extending a distance above the upper tapping hole is formed. When the supply of slag forming compounds is finished, the molten layer of slag is allowed to stay in the furnace for a predetermined period to ensure removal of phosphorous from the slag and into the ferrosilicon alloy. The upper tapping hole is then opened and the slag above the tapping hole is being tapped from the furnace. After tapping, the upper tapping hole is closed and further slag forming compounds are supplied to the furnace. When the phosphorous content in the ferrosilicon alloy has increased to a preset value, the ferrosilicon alloy is tapped from the lower tapping hole and the above described process is repeated. In this way it is obtained a semi-continuous, low cost production of low phosphorous calcium-silicate based slag.
- The present invention also relates to the use of the slag produced according to the method of the present invention for removal of boron and phosphorous from molten silicon.
- A layer of molten ferrosilicon alloy consisting of 85% by weight Fe and 15% by weight Si was provided at the bottom of an induction furnace. 120 grams of 10 quarts having a phosphorous content of 4 ppmw and 130 grams of lime having a phosphorous content of 35 ppm were added to the induction furnace and melted on the top of the molten ferrosilicon layer. The initial phosphorous content of the liquid slag was calculated to 20 ppmw based on the phosphorous content of quarts and lime.
- Three tests were run using different gas compositions for stirring the melt. The stirring gas was supplied through a graphite tube. After treatment the slag was tapped from the induction furnace and analysed with respect to phosphorous, boron, CaO, Si02 and Fe203. The results are shown in Table 1.
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TABLE 1 Chemical Analysis P* B CaO Si02 Fe203 Test No. Stirring gas [ppmw] [ppmw] [wt %] [wt %] [wt %] A Ar—5%H2 <2.5 8.1 53.44 46.48 0.12 B Ar—25%CO <2.5 8.4 53.36 46.55 <0.12 C Ar <2.5 8.1 53.01 47.60 0.12 *detection limit for P in slag: 2.5 ppmw (ICP) - The results in Table 1 show that the phosphorous content in the produced slags was below the detection limit of 2.5 ppm for all three slags. Based on calculations of mass balances from use of the produced slags in slag treatment of molten silicon, it was found that the phosphorous content of the three slags produced in fact was about 0.1 ppmw. Further, Table 1 shows that the content of Fe203 in the three slags was very low, indicating that only a minor amount of iron was transferred from the ferrosilicon alloy to the slag phase.
- The three slags A, Band C produced in Example 1 were used to remove boron and phosphorous from molten silicon. Molten metallurgical grade silicon containing 47 ppmw boron, 9 ppmw phosphorous and 0.25% by weight of iron was treated with the slags A, Band C produced in Example 1. The weight ratio of slag to silicon was 2.6 for all runs. The content of phosphorous, boron and iron in the used slags and in the treated silicon were analysed. The results are shown in Table 2.
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TABLE 2 Fe % by Pppmw Bppmw weight Slag in slag in Si in slag in Si In Si A 2.5 * 3 25.5 8.6 0.4 B 2.5 * 4 25.1 8.5 0.4 C 2.5 * 4 25.7 8.5 0.4 * detection limit for P in slag: 2.5 ppmw (ICP) - From the results in Table 2 it can be seen that a very good boron removal was obtained for all three slags and that the phosphorous content in the treated silicon was reduced from 9 to about 4 ppmw.
Claims (10)
Priority Applications (1)
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US12/501,725 US7854784B2 (en) | 2002-05-22 | 2009-07-13 | Calcium-silicate based slag for treatment of molten silicon |
Applications Claiming Priority (5)
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NO20022409A NO318092B1 (en) | 2002-05-22 | 2002-05-22 | Calcium-silicate-based slag, process for the preparation of calcium-silicate-based slag, and application for slag treatment of molten silicon |
NO20022409 | 2002-05-22 | ||
US10/515,583 US7918916B2 (en) | 2002-05-22 | 2003-03-17 | Calcium-silicate based slag for treatment of molten steel |
PCT/NO2003/000091 WO2003097528A1 (en) | 2002-05-22 | 2003-03-17 | A calcium-silicate based slag for treatment of molten silicon |
US12/501,725 US7854784B2 (en) | 2002-05-22 | 2009-07-13 | Calcium-silicate based slag for treatment of molten silicon |
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PCT/NO2003/000091 Division WO2003097528A1 (en) | 2002-05-22 | 2003-03-17 | A calcium-silicate based slag for treatment of molten silicon |
US10/515,583 Division US7918916B2 (en) | 2002-05-22 | 2003-03-17 | Calcium-silicate based slag for treatment of molten steel |
US10515583 Division | 2003-03-17 |
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US20090274608A1 true US20090274608A1 (en) | 2009-11-05 |
US7854784B2 US7854784B2 (en) | 2010-12-21 |
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US10/515,583 Active 2025-01-09 US7918916B2 (en) | 2002-05-22 | 2003-03-17 | Calcium-silicate based slag for treatment of molten steel |
US12/041,373 Expired - Lifetime US7879130B2 (en) | 2002-05-22 | 2008-03-03 | Calcium-silicate based slag for treatment of molten silicon |
US12/501,725 Expired - Lifetime US7854784B2 (en) | 2002-05-22 | 2009-07-13 | Calcium-silicate based slag for treatment of molten silicon |
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US12/041,373 Expired - Lifetime US7879130B2 (en) | 2002-05-22 | 2008-03-03 | Calcium-silicate based slag for treatment of molten silicon |
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US (3) | US7918916B2 (en) |
EP (1) | EP1517857B1 (en) |
JP (1) | JP4227956B2 (en) |
KR (1) | KR100635683B1 (en) |
CN (1) | CN1307094C (en) |
AU (1) | AU2003241215A1 (en) |
BR (1) | BR0311151B1 (en) |
CA (1) | CA2486439C (en) |
ES (1) | ES2639377T3 (en) |
NO (1) | NO318092B1 (en) |
WO (1) | WO2003097528A1 (en) |
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US9676632B2 (en) | 2012-06-25 | 2017-06-13 | Silicor Materials Inc. | Method for purifying silicon |
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US11780734B2 (en) | 2016-12-19 | 2023-10-10 | Norwegian University Of Science And Technology (Ntnu) | Process for the production of commercial grade silicon |
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US7682585B2 (en) | 2006-04-25 | 2010-03-23 | The Arizona Board Of Regents On Behalf Of The University Of Arizona | Silicon refining process |
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Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3711278A (en) * | 1969-04-23 | 1973-01-16 | Stora Kopparbergs Bergslags Ab | Method of manufacturing chromium alloyed steel |
US3871872A (en) * | 1973-05-30 | 1975-03-18 | Union Carbide Corp | Method for promoting metallurgical reactions in molten metal |
US4151264A (en) * | 1977-02-14 | 1979-04-24 | Wacker-Chemie Gmbh | Process of melting down and purifying silicon |
US4312700A (en) * | 1979-06-26 | 1982-01-26 | Helictronic Forschungs- Und Entwicklungs- Gesellschaft Fur Solarzellen-Grundstoffe Mbh | Method for making silicon rods |
US4340426A (en) * | 1979-06-09 | 1982-07-20 | Nippon Chemical Industrial Co., Ltd. | Additives for continuous casting of steel |
US4457903A (en) * | 1982-03-11 | 1984-07-03 | Heliotronic Forshungs Und Entwicklungsgesellschaft Fur Solarzellen Grundstoffe Mbh | Semicontinuous process for the production of pure silicon |
US4515600A (en) * | 1982-03-11 | 1985-05-07 | Heliotronic Forschungs-und Entwicklungsgesellschaft fur Solarzellen-Grundstoffe m.b.H. | Process for the removal of the slag portion from molten mixtures of slag and silicon using a semipermeable separating wall |
US4534791A (en) * | 1983-08-29 | 1985-08-13 | Wacker-Chemie Gmbh | Process for treating silicon and ferrosilicon with slag |
US4837376A (en) * | 1986-10-15 | 1989-06-06 | Bayer Aktiengesellschaft | Process for refining silicon and silicon purified thereby |
US5187126A (en) * | 1988-07-29 | 1993-02-16 | Nippon Chemical Industrial Co., Ltd. | Slag treatment material |
US5788945A (en) * | 1994-09-01 | 1998-08-04 | Elkem Asa | Method for refining of silicon |
US6368403B1 (en) * | 1997-08-28 | 2002-04-09 | Crystal Systems, Inc. | Method and apparatus for purifying silicon |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0002135B1 (en) * | 1977-11-21 | 1982-11-03 | Union Carbide Corporation | Improved refined metallurgical silicon and process for the production thereof |
DE3201312C2 (en) * | 1982-01-18 | 1983-12-22 | Skw Trostberg Ag, 8223 Trostberg | Process for purifying silicon |
GB2116959B (en) * | 1982-03-19 | 1985-09-04 | Atomic Energy Authority Uk | Materials suitable for use as thermal spraying powders |
JPH07206420A (en) * | 1994-01-10 | 1995-08-08 | Showa Alum Corp | Production of high-purity silicon |
WO1997003922A1 (en) * | 1994-01-10 | 1997-02-06 | Showa Aluminum Corporation | Process for producing high-purity silicon |
NO980139D0 (en) * | 1995-07-14 | 1998-01-13 | Showa Aluminum Corp | Process for producing high purity silicon |
CN1083396C (en) * | 1995-07-14 | 2002-04-24 | 昭和电工株式会社 | Process for producing high-purity silicon |
KR20090053807A (en) * | 2006-09-14 | 2009-05-27 | 실리슘 비캔커 인코포레이티드 | Process and apparatus for purifying low-grade silicon material |
-
2002
- 2002-05-22 NO NO20022409A patent/NO318092B1/en not_active IP Right Cessation
-
2003
- 2003-03-17 US US10/515,583 patent/US7918916B2/en active Active
- 2003-03-17 ES ES03730916.8T patent/ES2639377T3/en not_active Expired - Lifetime
- 2003-03-17 CA CA002486439A patent/CA2486439C/en not_active Expired - Lifetime
- 2003-03-17 BR BRPI0311151-2A patent/BR0311151B1/en active IP Right Grant
- 2003-03-17 JP JP2004505266A patent/JP4227956B2/en not_active Expired - Lifetime
- 2003-03-17 CN CNB038115255A patent/CN1307094C/en not_active Expired - Lifetime
- 2003-03-17 AU AU2003241215A patent/AU2003241215A1/en not_active Abandoned
- 2003-03-17 KR KR1020047018693A patent/KR100635683B1/en active IP Right Grant
- 2003-03-17 EP EP03730916.8A patent/EP1517857B1/en not_active Expired - Lifetime
- 2003-03-17 WO PCT/NO2003/000091 patent/WO2003097528A1/en active Application Filing
-
2008
- 2008-03-03 US US12/041,373 patent/US7879130B2/en not_active Expired - Lifetime
-
2009
- 2009-07-13 US US12/501,725 patent/US7854784B2/en not_active Expired - Lifetime
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3711278A (en) * | 1969-04-23 | 1973-01-16 | Stora Kopparbergs Bergslags Ab | Method of manufacturing chromium alloyed steel |
US3871872A (en) * | 1973-05-30 | 1975-03-18 | Union Carbide Corp | Method for promoting metallurgical reactions in molten metal |
US4151264A (en) * | 1977-02-14 | 1979-04-24 | Wacker-Chemie Gmbh | Process of melting down and purifying silicon |
US4340426A (en) * | 1979-06-09 | 1982-07-20 | Nippon Chemical Industrial Co., Ltd. | Additives for continuous casting of steel |
US4312700A (en) * | 1979-06-26 | 1982-01-26 | Helictronic Forschungs- Und Entwicklungs- Gesellschaft Fur Solarzellen-Grundstoffe Mbh | Method for making silicon rods |
US4457903A (en) * | 1982-03-11 | 1984-07-03 | Heliotronic Forshungs Und Entwicklungsgesellschaft Fur Solarzellen Grundstoffe Mbh | Semicontinuous process for the production of pure silicon |
US4515600A (en) * | 1982-03-11 | 1985-05-07 | Heliotronic Forschungs-und Entwicklungsgesellschaft fur Solarzellen-Grundstoffe m.b.H. | Process for the removal of the slag portion from molten mixtures of slag and silicon using a semipermeable separating wall |
US4534791A (en) * | 1983-08-29 | 1985-08-13 | Wacker-Chemie Gmbh | Process for treating silicon and ferrosilicon with slag |
US4837376A (en) * | 1986-10-15 | 1989-06-06 | Bayer Aktiengesellschaft | Process for refining silicon and silicon purified thereby |
US5187126A (en) * | 1988-07-29 | 1993-02-16 | Nippon Chemical Industrial Co., Ltd. | Slag treatment material |
US5788945A (en) * | 1994-09-01 | 1998-08-04 | Elkem Asa | Method for refining of silicon |
US6368403B1 (en) * | 1997-08-28 | 2002-04-09 | Crystal Systems, Inc. | Method and apparatus for purifying silicon |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9676632B2 (en) | 2012-06-25 | 2017-06-13 | Silicor Materials Inc. | Method for purifying silicon |
US10773963B2 (en) | 2012-06-25 | 2020-09-15 | Silicor Materials Inc. | Method of purifying aluminum and use of purified aluminum to purify silicon |
US11780734B2 (en) | 2016-12-19 | 2023-10-10 | Norwegian University Of Science And Technology (Ntnu) | Process for the production of commercial grade silicon |
Also Published As
Publication number | Publication date |
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AU2003241215A1 (en) | 2003-12-02 |
CA2486439C (en) | 2008-10-14 |
US7854784B2 (en) | 2010-12-21 |
WO2003097528A1 (en) | 2003-11-27 |
NO318092B1 (en) | 2005-01-31 |
EP1517857A1 (en) | 2005-03-30 |
CN1307094C (en) | 2007-03-28 |
US7879130B2 (en) | 2011-02-01 |
BR0311151A (en) | 2005-03-29 |
JP2005525988A (en) | 2005-09-02 |
NO20022409L (en) | 2003-11-24 |
BR0311151B1 (en) | 2012-01-24 |
JP4227956B2 (en) | 2009-02-18 |
US20050172757A1 (en) | 2005-08-11 |
CA2486439A1 (en) | 2003-11-27 |
KR20050016417A (en) | 2005-02-21 |
ES2639377T3 (en) | 2017-10-26 |
KR100635683B1 (en) | 2006-10-17 |
EP1517857B1 (en) | 2017-06-21 |
US7918916B2 (en) | 2011-04-05 |
US20080156145A1 (en) | 2008-07-03 |
CN1656015A (en) | 2005-08-17 |
NO20022409D0 (en) | 2002-05-22 |
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